Deburring and scraping tools utilizing scraping blades have already been known for many years. Such tools are utilized in the manufacturing of metal workpieces by smoothing sharp edges and removing burrs formed between adjacent surfaces. There is also a need for scraping internal grooves, for example threads, so as to clean and/or smooth the groove.
Known tools have a scraping blade mounted in a handle either directly or through a blade-holder. When such a scraping blade mounted in a handle is brought into contact with a curved sharp edge and rotated in a crank-like motion along the curved edge, a nicely obliqued face is obtained.
Many different blade configurations have been designed for the deburring of sharp edges of various shapes and at various positions on metallic parts as well as other rigid materials. However, some machined positions within workpieces, such as internal cylindrical grooves or internal threads, are inaccessible with known tools. Internal cylindrical grooves are very common in metal parts primarily for the placement of "O" rings and for hydraulic passages. Edges of internal cylindrical grooves cannot be deburred by known hand tools and the removal of burrs therefrom has to be carried out by special cutting tools mounted on a lathe and subsequently removing the burrs from the grooved edges one edge at a time, by machining them on the lathe. Such an operation is cumbersome, expensive and time-consuming.
After the metal part has been in use, internal grooves or threads may be marred or become clogged (e.g. with grease or the like). Again, it is necessary to have a tool suitable for cleaning or smoothing the groove.
It is thus the object of the present invention to provide simple hand tools for the deburring or scraping of internal grooves.